:root{
      --theme:#0B3D91;
      --ink:#17243b;
      --muted:#6d7890;
      --line:#dfe6f0;
      --soft:#f4f7fb;
      --white:#fff;
      --shadow:0 16px 45px rgba(20,45,86,.1);
      --radius:16px;
    }
    *{box-sizing:border-box}
    html{scroll-behavior:smooth}
    body{margin:0;color:var(--ink);background:#f7f9fc;font-family:"Microsoft YaHei","PingFang SC",Arial,sans-serif;line-height:1.7}
    a{color:inherit;text-decoration:none}
    img{max-width:100%;display:block}
    button{font:inherit}
    .container{width:min(1180px,calc(100% - 40px));margin:0 auto}
    .topbar{height:38px;background:#092d6b;color:#dbe8ff;font-size:13px}
    .topbar .container{height:100%;display:flex;align-items:center;justify-content:space-between}
    .topbar a{margin-left:20px;color:#dbe8ff}
    .header{position:relative;z-index:20;background:#fff;border-bottom:1px solid var(--line)}
    .header-inner{height:78px;display:flex;align-items:center;gap:28px}
    .logo{display:flex;align-items:center;gap:10px;min-width:190px;font-weight:800;color:var(--theme);font-size:19px}
    .logo img{width:34px;height:34px;object-fit:contain}
    .main-nav{flex:1}
    .nav-list{display:flex;align-items:center;justify-content:center;gap:4px;list-style:none;margin:0;padding:0}
    .nav-item{position:relative}
    .nav-link{display:flex;align-items:center;gap:5px;padding:27px 13px;color:#26344d;font-size:14px;white-space:nowrap}
    .nav-link:hover,.nav-link:focus{color:var(--theme)}
    .has-arrow:after{content:"⌄";font-size:13px;color:#8190a6}
    .dropdown-panel,.mega-menu{position:absolute;top:100%;left:50%;transform:translateX(-50%);visibility:hidden;opacity:0;pointer-events:none;background:#fff;border:1px solid var(--line);box-shadow:var(--shadow);transition:.2s ease}
    .dropdown-panel{width:270px;padding:12px;border-radius:0 0 12px 12px}
    .dropdown-panel a:not(.mega-footer){display:block;padding:10px 12px;border-bottom:1px solid #edf1f6;font-size:13px}
    .mega-menu{width:680px;padding:20px;border-radius:0 0 16px 16px}
    .nav-item:hover>.mega-menu,.nav-item:focus-within>.mega-menu,.nav-item:hover>.dropdown-panel,.nav-item:focus-within>.dropdown-panel{visibility:visible;opacity:1;pointer-events:auto}
    .mega-menu:before,.dropdown-panel:before{content:"";position:absolute;left:0;right:0;top:-12px;height:12px}
    .mega-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}
    .mega-card{display:block;min-height:86px;padding:11px;border:1px solid #e8edf5;border-radius:10px;background:#fbfcfe}
    .mega-card:hover{border-color:#9bb6e9;background:#f3f7ff}
    .mega-card img{width:34px;height:34px;object-fit:contain;margin-bottom:6px;border-radius:6px}
    .mega-card strong{display:block;font-size:13px;color:#1d3157;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
    .mega-card small{display:block;margin-top:3px;color:#7b879b;font-size:11px;line-height:1.5}
    .mega-footer{display:block;margin-top:15px;padding-top:13px;border-top:1px solid var(--line);font-size:13px;color:var(--theme);font-weight:700}
    .header-btns{display:flex;align-items:center;gap:14px;white-space:nowrap}
    .header-btns>a:first-child{color:var(--theme);font-size:13px}
    .account-link{background:var(--theme);color:#fff!important;padding:9px 14px;border-radius:8px;font-size:13px}
    .hamburger{display:none;border:0;background:transparent;padding:4px;cursor:pointer}
    .hamburger span{display:block;width:24px;height:2px;background:var(--ink);margin:5px 0;transition:.2s}
    .hamburger.active span:nth-child(1){transform:translateY(7px) rotate(45deg)}
    .hamburger.active span:nth-child(2){opacity:0}
    .hamburger.active span:nth-child(3){transform:translateY(-7px) rotate(-45deg)}
    .drawer-overlay{position:fixed;inset:0;background:rgba(5,17,38,.5);opacity:0;visibility:hidden;z-index:50;transition:.2s}
    .drawer-overlay.open{opacity:1;visibility:visible}
    .mobile-drawer{position:fixed;z-index:51;top:0;right:0;width:min(390px,88vw);height:100vh;background:#fff;transform:translateX(100%);transition:.25s ease;overflow:auto}
    .mobile-drawer.open{transform:translateX(0)}
    .drawer-head{display:flex;align-items:center;gap:15px;padding:20px;border-bottom:1px solid var(--line);color:var(--theme);font-weight:700}
    .drawer-head>a{margin-left:auto;background:var(--theme);color:#fff;padding:7px 12px;border-radius:7px;font-size:13px}
    .drawer-close{border:0;background:transparent;font-size:28px;color:#718096;cursor:pointer}
    .drawer-menu{padding:10px 20px 35px}
    .drawer-link,.drawer-toggle{display:block;width:100%;padding:14px 0;text-align:left;border:0;border-bottom:1px solid #edf0f5;background:none;color:var(--ink);font-size:15px;cursor:pointer}
    .drawer-toggle:after{content:"＋";float:right;color:#8290a5}
    .drawer-toggle.active:after{content:"－"}
    .drawer-submenu{display:none;padding:5px 0 8px 14px}
    .drawer-submenu.open{display:block}
    .drawer-submenu a{display:block;padding:8px 0;color:#65738a;font-size:13px}
    .footer{margin-top:70px;background:#10213d;color:#c7d3e7;padding:54px 0 20px}
    .footer-grid{display:grid;grid-template-columns:1.5fr 1fr 1fr 1fr;gap:35px}
    .footer h3{margin:0 0 15px;color:#fff;font-size:16px}
    .footer p{margin:8px 0;font-size:13px;line-height:1.9}
    .footer a{display:block;margin:8px 0;color:#c7d3e7;font-size:13px}
    .footer a:hover{color:#fff}
    .footer-bottom{margin-top:38px;padding-top:18px;border-top:1px solid rgba(255,255,255,.14);font-size:12px;color:#8fa1be;text-align:center}

    .product-page{padding:48px 0 10px}
    .crumbs{display:flex;gap:8px;align-items:center;color:#7a879b;font-size:13px;margin-bottom:25px}
    .crumbs a{color:var(--theme)}
    .product-hero{display:grid;grid-template-columns:minmax(0,1fr) 390px;gap:42px;align-items:start;background:#fff;border:1px solid var(--line);border-radius:20px;padding:35px;box-shadow:var(--shadow)}
    .product-copy h1{margin:0 0 14px;font-size:clamp(28px,4vw,44px);line-height:1.2;color:#112b58}
    .product-summary{color:#66758d;font-size:16px;margin:0 0 25px}
    .product-meta{display:flex;flex-wrap:wrap;gap:10px;margin:0 0 25px}
    .product-meta span{padding:7px 12px;background:#edf3ff;border-radius:20px;color:var(--theme);font-size:12px}
    .product-actions{display:flex;flex-wrap:wrap;gap:12px}
    .product-actions a{display:inline-flex;align-items:center;justify-content:center;padding:12px 20px;border-radius:9px;background:var(--theme);color:#fff;font-weight:700;font-size:14px}
    .product-actions a.secondary{background:#edf3ff;color:var(--theme)}
    .product-cover{min-height:280px;padding:22px;border-radius:16px;background:linear-gradient(145deg,#edf4ff,#dfeaff);display:flex;align-items:center;justify-content:center}
    .product-cover img{max-height:280px;width:100%;object-fit:contain;border-radius:10px}
    .product-layout{display:grid;grid-template-columns:minmax(0,1fr) 300px;gap:28px;margin-top:30px}
    .product-content-card,.related-card{background:#fff;border:1px solid var(--line);border-radius:16px;padding:28px}
    .product-content-card h2,.related-card h2{margin:0 0 20px;color:#173765;font-size:22px}
    .product-body{min-width:0;max-width:100%;overflow-x:auto;color:#43536c;font-size:15px}
    .product-body img,.product-body video{max-width:100%;height:auto}
    .product-body table{max-width:100%;display:block;overflow-x:auto;border-collapse:collapse}
    .product-body p{margin:0 0 1em}
    .product-body h2,.product-body h3{color:#173765}
    .product-info{display:grid;grid-template-columns:repeat(2,1fr);gap:10px;margin-bottom:25px}
    .product-info div{padding:12px;background:var(--soft);border-radius:9px}
    .product-info b{display:block;font-size:12px;color:#7b8799;font-weight:400}
    .product-info span{display:block;margin-top:3px;color:#1b3764;font-weight:700;font-size:14px}
    .related-list{display:grid;gap:13px}
    .related-item{display:grid;grid-template-columns:58px 1fr;gap:11px;align-items:center;padding:10px;border:1px solid #e8edf4;border-radius:10px}
    .related-item img{width:58px;height:58px;object-fit:contain;border-radius:7px;background:#f1f5fa}
    .related-item strong{display:block;color:#23416f;font-size:13px}
    .related-item small{display:block;color:#8792a4;font-size:11px;line-height:1.5;margin-top:3px}
    .product-bottom-meta{display:flex;justify-content:space-between;gap:15px;flex-wrap:wrap;color:#8995a8;font-size:12px;border-top:1px solid var(--line);margin-top:25px;padding-top:16px}

    @media(max-width:1050px){
      .nav-link{padding-left:8px;padding-right:8px}
      .logo{min-width:150px}
      .header-inner{gap:12px}
    }
    @media(max-width:800px){
      .container{width:min(100% - 28px,680px)}
      .topbar{height:auto;padding:8px 0}
      .topbar .container{display:block}
      .topbar .contact{display:block;margin-top:3px}
      .topbar a{margin:0 14px 0 0}
      .main-nav{display:none}
      .hamburger{display:block}
      .header-inner{height:68px}
      .logo{min-width:0;font-size:16px}
      .account-link{padding:8px 10px}
      .mega-menu,.dropdown-panel{display:none}
      .product-page{padding-top:28px}
      .product-hero{grid-template-columns:1fr;padding:22px;gap:24px}
      .product-cover{order:-1;min-height:210px}
      .product-layout{grid-template-columns:1fr}
      .product-content-card,.related-card{padding:21px}
      .footer-grid{grid-template-columns:1fr 1fr;gap:25px}
    }
    @media(max-width:520px){
      .header-btns>a:first-child{display:none}
      .product-copy h1{font-size:30px}
      .product-summary{font-size:14px}
      .product-cover{min-height:170px}
      .footer-grid{grid-template-columns:1fr}
      .footer{margin-top:40px;padding-top:38px}
    }